In order to uncompress the files you will need to use a compression utility,
such as the built-in features of OS X or Stuffit Expander.

Important note: The Patcher utility is used to patch form·Z, form·Z RenderZone, and form·Z RadioZity from v6.5.0 to the latest version. See the Patcher instructions included with the download for details using this utility. You will need to download the Patcher utility as well as the necessary patch files depending on what executables you need to patch. You must use this patcher for installing the 6.6.0 patch. Do not use any previous version of the patcher utility.

Download the patcher here first:PATCHER 6.6
A list of corrections is available: 6.6.0 Corrections

*NOTE: You must update any previous versions of form·Z to v6.5.6 before patching to v6.6.0